铅在镉在被金鱼吸收积累过程中的相互作用

采用混合体系暴露和顺次暴露的方法研究了铅和镉在被金鱼吸收过程中的相互作用。结果表明,混合暴露条件下,保持镉暴露量不变,增加铅的投放量,鳃镉与肝镉含量与单独暴露的结果无显著性差异,肾镉含量则随铅暴露浓度增加而减少。保持铅浓度不变,增加镉的投放理可导致鳃放肾铅含量下降。在镉、铅顺序暴露后则没有观测到锶、肝和肾铅含量的规律性变化。     

金鱼对铅和镉的吸收蓄积

研究了铅、镉暴露实验中金鱼不同器官经有收积累铅、镉的过程及蓄积量。结合到金鱼鳃上的铅、镉可用Langmuir吸附等温式描述。最大结合容量Bmax为：铅0.9424mmol/kg干重;镉17662μmol/kg条件稳定常数logK为：铅7.80;镉6.38。Hill结合特征常数为：铅1.012;镉1.175,表明金鱼鳃上仅有一种类型的Pb^2 或Cd^2 结合位点。鳃中铅、镉含量与血液含量以及血液铅、镉含量与肾、肝中的含量呈正相关关系。肾脏对铅、镉的蓄积量高于其他器官。     

西番莲对镉、铅的吸收累积特性

以紫果西番莲和黄果西番莲为试材进行盆栽试验,研究镉、铅处理后西番莲体内镉、铅含量变化。结果表明,镉、铅在西番莲体内分布的一般规律是枝蔓> 叶> 果。不同品种西番莲的镉含量未见显著差异,而铅含量则呈显著差异。西番莲枝蔓和叶对镉、铅的吸收量分别随着各自处理浓度的增加而增加;统计显示,西番莲枝蔓和叶的镉、铅含量与各自土壤的添加量呈极显著正相关。值得注意的是,西番莲对镉有较强的吸收能力(枝蔓和叶对土壤镉的富集系数均大于1),而对铅的吸收能力较差。在本试验中,铅处理浓度为1 000 mg/kg时,西番莲果实可食部分铅的含量也低于无公害果品标准,说明西番莲作为果树生产时,即使在铅含量较高的污染土上种植,也是安全的;但要特别注意镉的污染风险。     

镉长期暴露对黑斑蛙的氧化胁迫和抗氧化能力的影响

在实验条件下,将黑斑蛙暴露于12．5mg／L和25．0mg／L浓度的镉溶液中30d,分别测定了黑斑蛙在暴露10、20和30d时肝、肾组织中镉（Cd）含量、过氧化产物丙二醛（MDA）的含量、还原型谷胱甘肽（GSH）含量和超氧化物歧化酶（SOD）活性,以探讨镉对机体的脂质过氧化作用及机体的抗氧化损伤机制。实验结果表明,不同剂量组黑斑蛙肝、肾镉含量、MDA含量均随着镉暴露时间的延长而升高,且肝MDA含量与镉在肝中的蓄积量呈显著正相关（R^2=0．8643,n=9）。肝脏GSH含量随镉暴露时间的延长而被显著诱导,且与MDA含量呈显著正相关（R^2=0．5933,n=9）;肾GSH含量则随暴露时间的延长而显著下降,与MDA含量呈显著负相关（R^2=0．8609,n=9）。不同剂量组肝SOD活性随镉暴露时间的延长而升高,肾SOD活性在高剂量组随镉暴露时间的延长表现为先升高后回落下降的趋势。可见,在镉的长期暴露下,细胞膜过氧化增强是镉伤害机体的主要原因,而GSH含量、SOD活性的升高则可能是机体抗过氧化的机理之一。     

黑斑蛙精巢MDA和抗氧化酶对铅、镉暴露的生态毒性响应

以健康性成熟黑斑蛙为供试动物,以精巢组织丙二醛(MDA)含量、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和谷胱甘肽过氧化物酶(GSH-Px)活性为指标,进行了水体铅、镉暴露的生态毒性响应研究.结果表明:(1)精巢MDA含量随铅、镉暴露浓度的升高而明显增加,且呈明显的浓度-效应关系.说明低水平铅、镉的长期暴露对黑斑蛙精巢具有一定的损伤作用;(2)SOD活性在各处理组响应变化不明显,CAT、GSH-Px活性则被显著诱导,说明GSH-Px、CAT在铅、镉引起的精巢抗氧化损伤中起着重要作用;(3)3种抗氧化酶相比,GSH-Px活性对铅、镉暴露响应最敏感,SOD活性的响应最不明显,精巢GSH-Px活性是指示铅、镉暴露的优选生物标志物。     

铅在中华鲟幼鱼不同组织中的积累与排放

采用水溶液静态置换法,研究了中华鲟幼鱼在不同浓度Pb²⁺溶液(0、0.2、0.8和1.6mg·L^-1)中各组织铅的积累与排放.结果显示：中华鲟幼鱼各组织表现出随暴露浓度升高Pb积累增加的剂量-效应关系; Pb积累的基本模式为：骨(背骨板和软骨)和肌肉中积累量最高; 胃、肠和皮肤次之; 肝、鳃与脊索相对较低.暴露试验结束后进行了为期6周的Pb排放试验,结果表明：低浓度组(0.2 mg·L^-1)各组织中Pb含量与对照组无显著差异(P＜0.05);中浓度组(0.8 mg·L^-1)除鳃胃、软骨和肌肉以外,其余组织的Pb含量均显著高于对照组(P＜0.05);高浓度组(1.6 mg·L^-1)除肝、肠和皮肤以外,其余组织均显著高于对照组(P＜0.05).比较积累与排放发现,低、中浓度组中鳃、皮肤和肝的Pb含量高于积累时.推测中华鲟幼鱼经鳃、皮肤和消化道摄入Pb,主要经鳃和皮肤进行排放.     

湖北省双孢蘑菇子实体中重金属铅镉含量及来源分析

双孢蘑菇Agaricus bisporus子实体中重金属铅、镉含量分析结果表明,铅、镉的背景值含量分别为0.636mg/kg和0.127mg/kg,样品中铅含量的范围为0.087－2.40mg/kg,镉含量的范围为0.038－0.301mg/kg。在两种不同栽培模式下,子实体中铅含量均有显著差异,但镉的含量并无显著差异。相关性分析表明,子实体中铅来源于覆土而与培养料无关,而镉的来源与栽培方式有关,覆土和培养料中的镉含量均影响子实体中的镉含量。     

镉诱导金属硫蛋白在华溪蟹组织中的表达

采用体外暴露染毒法,研究了不同浓度与时间条件下,镉诱导河南华溪蟹(Sinopotamon henanense)金属硫蛋白(metallothionein,MT)在肝胰腺、肌肉、鳃和卵巢中的表达差异。镉浓度分别为0、14·5mg/L、29mg/L和58mg/L;处理时间依次为1d、3d和5d。利用镉血红蛋白饱和法和火焰原子吸收分光光度法(AAS)测定MT的蛋白含量。结果显示,用不同的染毒浓度和处理时间,镉在组织中诱导产生MT的含量有较大差异,其中肝胰腺MT的诱导量最大,变化规律也最明显;肌肉中也有较大量MT的表达;而鳃和卵巢MT的诱导量均较低。此外,本文分析了镉的浓度与时间梯度对诱导MT表达的影响与毒性效应机制。结论:组织不同,染毒浓度及时间不同,镉诱导MT的表达也不同,具有一定的组织差异性和规律性。     

镉对长江华溪蟹酶活性及脂质过氧化的影响

本实验于2005年3-7月,采用急性毒性实验方法,研究了镉(Cd)对长江华溪蟹(Sinopotamon yangtsekiense)酶活性及脂质过氧化产物的影响.Cd处理设5个浓度组,分别为7.25mg/L、14.5mg/L、29mg/L、58mg/L和116mg/L,实验同时设对照组.分别在24h、48h、72h和96h取肝胰腺和鳃进行超氧化物歧化酶(SOD)、谷胱甘肽过氧化物酶(GSH-Px)活性的测定和脂质过氧化产物丙二醛(MDA)含量的测定.结果显示,在实验剂量范围内,随着镉浓度的增加和处理时间的延长,SOD和GSH-Px的活性均呈现先增高后降低的趋势,并存在组织差异性;而组织中MDA的含量随镉浓度的增加和处理时间的延长而升高.当处理时间为48h、Cd浓度为14.5mg/L时,肝胰腺和鳃中SOD活性均达最大值,较对照组差异极显著;当处理时间为48h、Cd浓度为7.25mg/L时,肝胰腺中GSH-Px活性达最大值,较对照组差异极显著;当处理时间为24h、Cd浓度为14.5mg/L时,鳃中GSH-Px活性达最大值,较对照组差异极显著.伴随处理时间和Cd浓度的增加,SOD和GSH-Px的活性开始逐渐下降.肝胰腺和鳃中GSH-Px/SOD的比值在对照组中处于平衡状态,但是在处理组中失去了平衡,有降低的趋势.结论:SOD与GSH-Px的活性和MDA含量的变化可以灵敏地反映Cd的胁迫程度及毒性大小.     

苯并[a]芘暴露对三疣梭子蟹鳃、肝胰腺组织毒理学指标的影响

本文研究了三疣梭子蟹(Portunus trituberculatus)在对苯并[a]芘(BaP)富集(15 d)、释放(15d)过程中其鳃和肝胰腺组织的4种毒理学指标的响应.4种毒理学指标分别为7-乙氧基异吩噁唑酮-脱乙基酶(EROD)、谷胱甘肽硫转移酶(GST)、超氧化物歧化酶(SOD)和脂质过氧化(LPO).设置了0.05 μg/L和0.45 μg/L两个实验组以及海水和丙酮对照组.结果显示,在富集阶段,与海水对照组相比,第1天时0.05 μg/L和0.45μg/L实验组鳃、肝胰腺组织的各毒理指标均显著受到诱导(P＜0.05),诱导程度随BaP暴露浓度的增加而增大.而后鳃、肝胰腺组织的EROD、GST活性以及鳃组织的SOD活性达到峰值后下降,肝胰腺组织的SOD活性以及鳃、肝胰腺组织的丙二醛(MDA)含量则持续增加.鳃组织的EROD、GST、SOD活性到达峰值时间早于肝胰腺组织,其活性以及MDA含量也低于肝胰腺组织.在释放阶段,0.45pg/L实验组鳃组织的SOD活性,0.05μ-g/L和0.45 μg/L两个实验组肝胰腺组织的SOD活性均依然显著高于同期海水对照组水平(P＜0.05),其余各浓度实验组鳃、肝胰腺组织均能恢复到同期海水对照组水平(P＞ 0.05).实验结果表明,三疣梭子蟹的鳃组织对于BaP暴露响应时间比肝胰腺组织更早,但均具有一定的恢复能力.     

白蚁与动物及微生物的共生类型及其机制

综述了白蚁螱客的主要种类、共生关系及相关机制的研究进展。白蚁螱客中,已报道的动物种类达170种。在与动物的共生关系中存在偏利共生（宾主共栖和异种共栖）、互利共生和无关共生三种;在与微生物的共生关系中,存在与内生菌（原生动物、细菌、真菌和放线菌）和外生菌（蚁巢伞菌等）间的互利关系。指出了白蚁与螱客研究中存在的问题,给出了解决方案,并提出了今后可能的研究热点或方向,为白蚁的综合利用（如纤维素酶）及今后研究物种间的协同进化提供了基础资料。     

Relative and combined effects of ethanol and protein deficiency on strontium and barium bone content and fecal and urinary excretion

To elucidate accumulation of minerals in human iliac arteries with aging, the content of minerals was analyzed by inductively coupled plasma atomic emission spectrometry. Bilateral common, internal, and external iliac arteries of 16 men and 8 women, ranging ages from 65 to 93 yr, were examined. It was found that an extremely high accumulation of calcium and phosphorus occurred in the common iliac artery at old age, being higher than that of the internal and external iliac arteries. It should be noted that the accumulation of calcium and phosphorus is the highest in the common iliac artery among the human arteries examined to date. Regarding sexual differences, the content of calcium and phosphorus in the common and internal iliac arteries was higher in women than in men, whereas their content in the external iliac artery was lower in women than in men.     

New amino-dithiaphospholanes and phosphoramidodithioites and their rhodium and iridium complexes

New sulfur derivatives of phosphoramidite ligands were synthesized and the impact of the sulfur unit on the spectroscopic properties of their rhodium and iridium complexes was investigated. The new ligands Bn₂NPSCH₂CH₂S^a(P-S^a) (Bn = benzyl, 4), Bn₂NPSCHCHS^a(CH₂)₃C^aH₂(P-S^a)(C^a-S^a) (6) and Bn₂NP(4-XC₆H₄OMe)₂ (X = S, 7a; X = O, 7b) were converted to the rhodium and iridium complexes trans-[Rh(CO)Cl(L)₂] (L = 4, 6, 7), [RhCl(COD)(L)] (L = 4, 6, 7), [IrCl(COD)(7a)] and [IrCl₂Cp∗(6)]. For comparison, some phosphoramidite complexes of these formulations also were synthesized. The new metal complexes were spectroscopically analyzed. For the carbonyl complexes, the ν_CO IR stretching frequencies were lower than for the corresponding phosphite and phosphoramidite ligands. The ¹J_PRh coupling constants for the rhodium complexes with the new ligands were also smaller than for the respective phosphoramidite and phosphite complexes. Finally, the ¹J_PSe coupling constants of the selenides of the new ligands were lower than those of the phosphoramidite ligands but higher than for PPh₃. The spectroscopic data reveal that the new thio ligands 4, 6 and 7a are more electron donating than phosphites and phosphoramidites but less electron donating than PPh₃.     

Astrocytes and Synaptosomes Transport and Metabolize Lactate and Acetate Differently

Astrocytes transport the monocarboxylate acetate, but synaptosomes do not. The reason for this is unknown, because both preparations express monocarboxylate transporters (MCT). The transport and metabolism of lactate, another monocarboxylate, was examined in these two preparations, and the results were compared to those for acetate. Lactate transport is more rapid in astrocytes than in synaptosomes, but of lower affinity (Kms of 17 and 4 mM, respectively). Lactate (0.2 mM) is metabolized to CO2 more rapidly in synaptosomes than in astrocytes (rates of 0.37 and 0.07 nmol x mg protein(-1) x min(-1), respectively). The reason for this is unclear, but cellular differences in lactate dehydrogenase isotype expression may be involved. Acetate is metabolized to CO2 more rapidly in astrocytes than in synaptosomes (rates of 0.43 and 0.02 nmol x mg protein(-1) x min(-1), respectively). This is likely due to cellular differences in the expression of monocarboxylate transporter subtypes.     

Rapporteur report: Basics and technology and metrology and standards

The first and second sessions of the Workshop focussed on the basics of ultrasound and infrasound, their applications in both industry and medicine, and metrology and protection standards for ultrasound applications.     

Prostaglandin and thromboxane production by human and guinea-pig macrophages and leucocytes

The ability of partially purified human and guinea-pig haematogenous cell populations, when cultured in vitro, to metabolise arachidonic acid (AA) has been studied. Supernatants from 24 hour cell culture have been subjected to analysis for products of AA metabolism by gas chromatography with electron-capture detection.The cell types studied were human peripheral blood monocytes (both glass adherent and non-adherent), neutrophils, eosinophils and leukemic leucocytes; thoracic duct lymphocytes and lung alveolar macrophages. From the guinea-pig, induced and non-induced macrophage or neutrophil enriched peritoneal exudate populations, lymph node cells, peritoneal eosinophils and peripheral blood platelets were examined. Supernatants were assayed for the presence of PGE₂, PGD₂, PGF_2α, TXB₂ and 6-keto-PGF_1α. In all types studied PGE₂ and TXB₂ were the major products formed. The identification of PGE₂ and TXB₂ was confirmed by GC/MS with multiple ion monitoring.The results have been compared with other reports and their possible significance discussed in relation to the proposed role of prostaglandins as mediators and modulators in immunopathology.     

Cytoskeleton and mitochondrial morphology and function

It has been well established that the cytoskeleton is an essential modulator of cell morphology and motility, intracytoplasmic transport and mitosis, however cytoskeletal linkage to the organelles has not been unequivocally demonstrated. Indeed, cytoskeleton appears to be essential in determining and modulating gene phenotype as a function of cellular environment. According to recent studies, the organization of the cytoskeleton network together with associated protein(s) could be essential in regulating mitochondrial function and particularly the permeability of the mitochondrial outer membrane to ADP. The aim of this chapter is to summarize the main properties of the cytoskeletal environment of mitochondria and the possible role(s) of this network in mitochondrial function in myocytes.     

Cross-reactivity between storage and dust mites and between mites and shrimp

Many patients have sensitivities to multiple species of storage and house dust mites. It is not clear if this is because patients have multiple sensitivities to species-specific mite allergens or if these mites share many cross-reacting allergens. Our objective was to further define the cross-allergenicity between several species of storage and house dust mites using crossed-immunoelectrophoresis (CIE), crossed-radioimmunoelectrophoresis (CRIE), immunoblotting, and ELISA. CIE and CRIE reactions revealed that storage mites shared two cross-antigenic molecules and one of these bound IgE in a serum pool from mite allergic patients. Antibody in anti-sera built to each species of mite recognized many SDS–PAGE resolved proteins of other mite species and this suggested the potential for other cross-reactive allergens. Among patient sera, IgE bound to many different proteins but few had IgE that bound to a protein with common molecular weights across the mite species and this suggested mostly species-specific allergens. Antiserum built to each mite species precipitated one protein in shrimp extracts that bound anti-Der p 10 (tropomyosin) and IgE in the serum pool. Anti-Der p 10 showed strong binding to shrimp tropomyosin but very little to any of the mite proteins. ELISA showed the mite extracts contained very little tropomyosin. The storage and dust mites investigated contain mostly species-specific allergens and very small amounts of the pan-allergen tropomyosin compared to shrimp and snail.